I tend to do 95% of my quilts as hand pieced, and have made several Irish Chain quilts by hand. The thing that really helps me is to use graph paper to color out my "rows", then to sort my pieces out exactly as I color them out. This is a little extra step, but then I don't have to think about it when I am sewing - just pick up the next piece, and go/
I know it probably isn't necessary, but I take a tiny backstitch at the beginning and end of each block, as well aseach time I pull up the thread. My LAQ has often commented on how nice my piecing is